Urgent search and rescue at the Baltimore bridge faces difficult conditions

The urgent 18-hour search for people believed to have plunged into the cold waters beneath Baltimore’s Francis Scott Key Bridge on Tuesday was complicated by perilous conditions, as the steel wreckage created obstacles for rescuers and low temperatures gave victims a short window for survival.The water’s swift current, murkiness and 50-foot depth — plus a lack of certainty about just how many cars or people could have been caught in the collapse — handed emergency responders a monumental task, authorities and disaster response experts said.The sweeping response that unfolded…